Certain non-endocrine tumors have been reported to produce polypeptide hormones. For instance, the formation of adrenocorticotropic hormone (ACTH) and "big" or precursor ACTH by lung tumors in man is well known. The proposed studies will attempt (1) to correlate the synthesis of ACTH as detected by radioimmunoassay and immunohistochemical techniques with the various stages of tumor growth, (2) to examine the possible formation de novo of polypeptide hormones in vitro in tracheal organ cultures in the presence of chemical carcinogens, and (3) to develop sensitive radioimmunoassay procedures that can be used for the diagnosis, management, and early detection of bronchogenic carcinomas.